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51.
Toshikatsu Koga 《Theoretical chemistry accounts》1997,95(3-4):113-130
The Hartree-Fock electron density has an important property that it is identical to the exact density to first order in the
perturbation theory. For the neutral atoms from He (Z = 2) to Lr (Z = 103) in their ground state, we report an accurate analytical
approximation F(r) to the spherically averaged electron densityρ(r) obtained by the numerical Hartree-Fock method. The present density functionF(r) is expressed by a linear combination of reasonable number (not more than 30) of basis functionsr
ni
exp(- ζ
i
r), and has the following properties: (i)F(r) is nonnegative, (ii)F(tr) is normalized, (iii)F(r) reproduces the Hartree-Fock moments <r
k
> (k = −2 to +6), (iv)F(0) is equal toρ(0), (v)F′(0) satisfies the cusp condition, and (vi)F(r) has the correct exponential decay in the long-range asymptotic region. 相似文献
52.
Ryo Yoshida Hisao Ichijo Toshikatsu Hakuta Tomohiko Yamaguchi 《Macromolecular rapid communications》1995,16(4):305-310
Novel gel systems demonstrating rhythmically pulsatile mechanical motion similar to that of a heartbeat were developed. Self-oscillations of swelling and deswelling for the polymer hydrogels were realized by coupling pH and temperature sensitive hydrogels with a non-linear chemical reaction in the external solution media. The novel gel dynamics exhibiting cyclic and rhythmical oscillations may establish a new concept for functional materials that work under dynamic oscillating states. 相似文献
53.
Masahiro Sekiya Takeshi Noro You Osanai Toshikatsu Koga 《Theoretical chemistry accounts》2001,106(4):297-300
Contracted Gaussian-type function sets are proposed for polarization functions of the atoms Ga–Kr and In–Xe. We also report
polarization functions for Ca and Sr. A segmented contraction scheme is used for its compactness and computational efficiency.
The contraction coefficients and orbital exponents are fully optimized to minimize the deviation from accurate atomic natural
orbitals. The present polarization functions yield more than 99% of atomic correlation energies predicted by accurate natural
orbitals of the same size.
Received: 23 February 2001 / Accepted: 19 April 2001 / Published online: 13 June 2001 相似文献
54.
For the singly charged 53 cations from Li+ to Cs+ and 43 anions from H− to I− in their ground states, spherically averaged electron-pair intracule (relative-motion) density h(u), extracule (center-of-mass-motion) density d(R), and their moments un and Rn are examined, where u and R are the interelectronic distance and the center-of-mass radius of a pair of electrons, respectively. The intracule and extracule densities of all the 96 ions are found to be monotonically decreasing functions, as for neutral atoms. Approximate relations d(R)8h(2R) and un/Rn2n are confirmed to be valid for the charged atoms as well. 相似文献
55.
56.
A kinetic energy analysis of total energy differences in 115 atomic multiplet states is presented. We show by numerical restricted Hartree—Fock calculations that there is a reasonably accurate linear relationship between the kinetic energy of the electrons in open subshells and the total energy within a manifold of states arising from the same spn or s2pn (n = 2,3,4) electron configuration in main-group atoms. © 1996 John Wiley & Sons, Inc. 相似文献
57.
58.
Akira Sakakura Kouichi Suzuki Hirotaka Katsuzaki Takashi Komiya Toshikatsu Imamura Yasuo Aizono Kunio Imai 《Tetrahedron letters》2005,46(52):9057-9059
The ‘Hanasanagitake’ mushroom, Isaria japonica, is a folk medicine and a traditional health food. Fractionation of the 60% ethanol extract of the mushroom, guided by the antioxidant activity test, led to the isolation of a new pseudo-di-peptide, and it was called ‘hanasanagin’. Spectral analysis and chemical transformation determined the structure of hanasanagin as 3,4-diguanidinobutanoyl-DOPA. 相似文献
59.
For statistically uncorrelated wave functions, the electron density ρ(r) is known to be an extremum function of the generalized electron-pair density g(q;a,b), which smoothly connects ρ(r), the electron-pair intracule (relative motion) density h(u), and the electron-pair extracule (center-of-mass motion) density d(R). The present systematic examination of the numerical Hartree–Fock results of moments rn, un, Rn and density values at the origin ρ(0), h(0), d(0) for 102 neutral atoms and 96 singly charged ions suggests that ρ(r) is local maximum for a small q and is local minimum for a large q of the function g(q;a,b). Analogous results are obtained for the momentum-space counterparts Π(p) and
. 相似文献
60.
Masahiro Sekiya Takeshi Noro Toshikatsu Koga Tsuyoshi Shimazaki 《Theoretical chemistry accounts》2012,131(7):1-8
For the 15 lanthanide atoms 57La through 71Lu, we report Sapporo-DK-nZP sets (n?=?D, T, Q), which are natural extensions of the Sapporo-(DK)-nZP sets for lighter atoms and efficiently incorporate the correlation among electrons in the N through P shells as well as the relativistic effect. The present sets well describe the correlation among the 4s and 4p electrons, which are important in the excitation of 4f electrons. Atomic test calculations of 57La, 58Ce, 59Pr, and 60Nd at configuration interaction with the Davidson correction level of theory confirm high performance of the present basis sets. Molecular test calculations are carried out for 57LaF and 70YbF diatomics at the coupled-cluster level of theory. The calculated spectroscopic constants approach smoothly to the experimental values as the quality of the basis set increases. 相似文献